1. Field of the Invention
This invention relates to an ink transfer member position adjusting method and apparatus of a rotary stencil printing press such as a rotary screen printing press.
2. Description of the Related Art
In screen printing using a rotary screen printing press, ink is placed in a screen printing forme, and a squeegee or a doctor roller, as an ink transfer member, is pressed against the screen printing forme, whereby the ink is transferred to a printing surface of paper via holes. Pressure, which the squeegee or the doctor roller exerts on the screen printing forme, affects a printing quality, and thus needs to be adjusted in accordance with an image area and a material to be printed.
Fine adjustment of the throw-on position of the squeegee or the doctor roller with respect to the screen printing forme during printing has been made manually by an operator who uses a tool to adjust a position adjusting mechanism for the squeegee or the doctor roller present in a rotary screen printing unit.
Thus, the operator is burdened, and may have to repeat motions, such as manual adjustment in the rotary screen printing unit, followed by confirmation of the resulting product, further followed by manual adjustment in the rotary screen printing unit. As noted here, the adjustment operation takes time, posing the problem that a large amount of wasted paper occurs.
Moreover, the squeegee or the doctor roller in the rotary screen printing press always contacts the screen printing forme (i.e., its inner peripheral surface) during printing, and is thus worn. After its use for a certain period, therefore, a corresponding fine adjustment has to be made. Repeated fine adjustment has resulted in a decreased rate of operation, and has aroused the problem of wasted paper occurrence.
The present invention has been accomplished in light of the above-described problems. It is an object of the invention to provide an ink transfer member position adjusting method and apparatus of a rotary stencil printing press, which can automate the fine adjustment of the throw-on position of an ink transfer member with respect to a stencil printing plate, to lessen burden on the operator and cut down on the adjusting time, thereby increasing the rate of operation and decreasing wasted paper.